Simulations consistently show the orb phenomena behave as self-replicating probes; more specifically, the sightings of orbs ejecting orbs, and orbs coalescing into a single orb, match the expected behaviour for a self-replicating probe.

Freitas (1980) outlines the specifics of a SRP, estimating the mass of each component of the spacecraft, and the material the spacecraft would need to accumulate to be able to produce a copy of itself and provide fuel. They suggest that a spacecraft may capture comets and use atmospheric mining to acquire these materials. They state that in their minds there is “little doubt that such a machine can, in theory, be designed”.